The mean time to failure (MTTF) was measured for a statistically significant population of planar In0.53Ga0.47As/InP heterostructure p-i-n photodetectors at several elevated temperatures. The ...probability for failure is fit to a log-normal distribution, with the result that the width of the failure distribution is sigma = 0.55 +/- 0.2, and is roughly independent of temperature. From the temperature dependence of MTTF data, it is found that the failure mechanism is thermally activated, with an activation energy of less than 1.5 +/- 0.2 eV measured in the temperature range of 170-250 C. This extrapolates to a MTTF of less than 0.1 failure in 109h (or less than 0.1 FIT) at 70 C, indicating that such devices are useful for systems requiring extremely high reliable components, even if operated at elevated temperatures for significant time periods. This activation energy is the highest value reported for In0.53Ga0.47As/InP photodetectors, and is significantly higher than the energies of 0.85 eV often suspected for these devices. (I.E.)
Cell surfaces and intercellular matrixes contain acidic residues, making them negatively charged. Antibodies are basic, positively charged glycoproteins. Therefore the potential for nonspecific ionic ...interaction exists, which could increase the background activity. Modification of antibodies with negatively charge-modified polymers have been shown to reduce this nonspecific background activity. This study was performed to investigate the appropriateness of different cross-linkers used covalently to link the chelating negatively charge-modified polylysine to antimyosin Fab (AM-Fab). The cross-linking was performed through peptide (AM-I) or thioether (AM-II) bonds. The in vitro evaluation of the immunointegrity and the in vivo assessment were performed to investigate the potential for reduction of nontarget background activity. Furthermore, the role of the charge of the polymers (whether completely negatively charge modified by succinylation AM-IIs or only partially negatively charge modified AM-IIns) was also assessed.
All polymer-modified preparations (AM-I, AM-IIs, and AM-IIns) retained the immunoreactivities relative to the unmodified or conventional diethylenetriaminepentaacetic acid-coupled AM-Fab as assessed by radioimmunoassay or enzyme-linked immunosorbent assay. These polymer-modified preparations labeled with 111In were assessed in 13 rabbits with acute experimental myocardial infarction. Acute infarcts were produced by 40 minutes of left anterior descending coronary artery occlusion followed by reperfusion. At between 10 and 30 minutes of reperfusion, 10.4 +/- 1.8 mBq 111In-AM-I (10 to 20 micrograms; n = 7) or 11.4 +/- 2.3 mBq 111In-AM-II (n or ns) (20 to 25 micrograms; n = 6) was administered intravenously. Gamma imaging was performed in the left lateral position and arterial blood samples were withdrawn serially for the next 3 hours. At the end of the final imaging session, AM-I uptake was determined to be 1.09% +/- 0.11% (mean percent injected dose per gram myocardium +/- SEM) in 20 infarcted myocardial segments from seven rabbits, compared with 0.031% +/- 0.003% in 20 normal myocardial segments (infarct/normal myocardial ratio 53.9 +/- 18.41). The mean percent injected dose of 111In-labeled thioether-linked AM-Fab preparations in nine infarcted myocardial segments from each group was 0.067% +/- 0.008% (infarct/normal myocardial ratio 9.0 +/- 1.5) and 0.144% +/- 0.011% (infarct/normal myocardial ratio 10.2 +/- 1.9) with AM-IIs (n = 3) and AM-IIns (n = 3), respectively (p < 0.0001). The non-target organ distribution of the AM-I and AM-IIs was similar. AM-IIns preparation resulted in high non-target organ activities.
This study shows that the charge of the antibody can be manipulated favorably by cross-linking with negatively charged polymers, which results in the reduced in vivo non-target organ activities. Charge modification does not adversely affect the apparent affinity of the antibody. However, the type of cross-linkers used may significantly influence the in vivo stability of the modified antibody preparations for target organ visualization. These data may find potential application in future clinical imaging protocols.
Performance of the ATLAS hadronic end-cap calorimeter in beam tests Dowler, B; Pinfold, J; Soukup, J ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2002, Letnik:
482, Številka:
1-2
Journal Article
Recenzirano
Odprti dostop
Modules of the ATLAS liquid argon Hadronic End-cap Calorimeter (HEC) were exposed to beams of electrons, muons and pions in the energy range 6⩽E⩽200GeV at the CERN SPS. A description of the HEC and ...of the beam test setup are given. Results on the energy response and resolution are presented and compared with simulations. The ATLAS energy resolution for jets in the end-cap region is inferred and meets the ATLAS requirements.
The dark current properties of In(x)Ga(1-x)As photodiodes, where < e1 > x < /e1 > is varied from 0.53 to 0.82 for extending the long wavelength cutoff from 1.7 to 2.6 mum, are described. Detailed ...analyses of optoelectrical parameters of In(0.82)Ga (0.1)As photodiodes are presented. Dark current, which is a critical parameter and limits the operation of the photodiode, is analyzed and compared with the experimental values. Typical characteristics of photodiodes with cutoff wavelengths of 1.7 mum ( < e1 > x < /e1 > =0.53), 2.2 mum ( < e1 > x < /e1 > =0.72), and 2.6 mum ( < e1 > x < /e1 > =0.82) are presented. The typical and best values of the dark currents obtained are presented
A significant (2-5x) reduction in 1/ < e1 > f < /e1 > noise was observed in In(0.53)Ga(0.47)As photodetector arrays read out by a PMOS multiplexer, when the epitaxial InP cap layer doping was changed ...from undoped to sulfur-doped n type of about 3x10(16) cm(-3). A further decrease was observed when the InP buffer layer was also changed from undoped to sulfur-doped n type of about 5x10(17) cm(-3). Data was presented for the variation of 1/ < e1 > f < /e1 > noise, within a temperature range of 18 deg C to -40 deg C. Surface states at the InP cap/SiN interface appears to be the primary source of 1/ < e1 > f < /e1 > noise, with the bulk states at the n(-)In(0.53)Ga(0.47)As buffer hetero-interface as a secondary source. Increased n-type doping in the high-bandgap InP cap and buffer layers may reduce electron trapping, and thus 1/ < e1 > f < /e1 > noise. The measured noise spectrum of InGaAs photodetectors varies as < e1 > f < /e1 > (y) with y being approximately -0.45 for device structures with doped and undoped InP can layers. For a doped InP buffer layer, this value of y is -0.3
This paper describes an innovative test strategy comprising a compliant elastomer mesh for testing fine pitch wafer-level package (WLP) devices. The test probe, hardware, and sample preparation ...processes are detailed. The components of the test hardware socket such as the SMA connectors, coplanar transmission lines on the PCB, via, off-chip interconnect, and elastomer mesh probe have been modeled. A complete system-level model, with off-chip interconnects on the WLP device pads, has been developed. The measurement and model demonstrate that the prototype test socket performs at 5 GHz with an insertion loss of about 3 dB. WLP device with Bed-of-Nail interconnects are characterized. Functional test features of the system are also addressed.
The mean time to failure (MTTF) was measured for a statistically significant population of planar In(0.53)Ga(0.47)As/InP heterostructure p-i-n photodetectors at several elevated temperatures. The ...probability for failure is fit to a log-normal distribution, with the result that the width of the failure distribution is sigma=0.55+/-0.2, and is roughly independent of temperature. From the temperature dependence of MTTF data, it is found that the failure mechanism is thermally activated, with an activation energy of less than 1.5+/-0.2 eV measured in the temperature range of 170-250 deg C. This extrapolates to a MTTF of less than 0.1 failure in 10(9) h (or < 0.1 FIT) at 70 deg C, indicating that such devices are useful for systems requiring extremely high reliable components, even if operated at elevated temperatures for significant time periods. This activation energy is the highest value reported for In(0.53)Ga(0.47)As/InP photodetectors, and is significantly higher than the energies of ~0.85 eV often suspected for these devices
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